#grades{
    width: 250px;
    height: auto;
    list-style: none;
    margin:0 auto ;
}
#grades li{
    list-style: none;
    float: left;
    border: 1px solid #888888;
    cursor:pointer;
    padding: 0 10px;
    margin:0 3px;

}
.message{
    font-family: "Microsoft Yahei", Helvetica, Arial, sans-serif;
    font-size: 20px;
    line-height: 1.42857143;
    color: #333;
}